All Supported Indicators and Functions
BBANDS Bollinger Bands
DEMA Double Exponential Moving Average
EMA Exponential Moving Average
HT_TRENDLINE Hilbert Transform - Instantaneous Trendline
KAMA Kaufman Adaptive Moving Average
MA Moving average
MAMA MESA Adaptive Moving Average
MAVP Moving average with variable period
MIDPOINT MidPoint over period
MIDPRICE Midpoint Price over period
SAR Parabolic SAR
SAREXT Parabolic SAR - Extended
SMA Simple Moving Average
T3 Triple Exponential Moving Average (T3)
TEMA Triple Exponential Moving Average
TRIMA Triangular Moving Average
WMA Weighted Moving Average
ADX Average Directional Movement Index
ADXR Average Directional Movement Index Rating
APO Absolute Price Oscillator
AROON Aroon
AROONOSC Aroon Oscillator
BOP Balance Of Power
CCI Commodity Channel Index
CMO Chande Momentum Oscillator
DX Directional Movement Index
MACD Moving Average Convergence/Divergence
MACDEXT MACD with controllable MA type
MACDFIX Moving Average Convergence/Divergence Fix 12/26
MFI Money Flow Index
MINUS_DI Minus Directional Indicator
MINUS_DM Minus Directional Movement
MOM Momentum
PLUS_DI Plus Directional Indicator
PLUS_DM Plus Directional Movement
PPO Percentage Price Oscillator
ROC Rate of change : ((price/prevPrice)-1)*100
ROCP Rate of change Percentage: (price-prevPrice)/prevPrice
ROCR Rate of change ratio: (price/prevPrice)
ROCR100 Rate of change ratio 100 scale: (price/prevPrice)*100
RSI Relative Strength Index
STOCH Stochastic
STOCHF Stochastic Fast
STOCHRSI Stochastic Relative Strength Index
TRIX 1-day Rate-Of-Change (ROC) of a Triple Smooth EMA
ULTOSC Ultimate Oscillator
WILLR Williams' %R
AD Chaikin A/D Line
ADOSC Chaikin A/D Oscillator
OBV On Balance Volume
HT_DCPERIOD Hilbert Transform - Dominant Cycle Period
HT_DCPHASE Hilbert Transform - Dominant Cycle Phase
HT_PHASOR Hilbert Transform - Phasor Components
HT_SINE Hilbert Transform - SineWave
HT_TRENDMODE Hilbert Transform - Trend vs Cycle Mode
AVGPRICE Average Price
MEDPRICE Median Price
TYPPRICE Typical Price
WCLPRICE Weighted Close Price
ATR Average True Range
NATR Normalized Average True Range
TRANGE True Range
CDL2CROWS Two Crows
CDL3BLACKCROWS Three Black Crows
CDL3INSIDE Three Inside Up/Down
CDL3LINESTRIKE Three-Line Strike
CDL3OUTSIDE Three Outside Up/Down
CDL3STARSINSOUTH Three Stars In The South
CDL3WHITESOLDIERS Three Advancing White Soldiers
CDLABANDONEDBABY Abandoned Baby
CDLADVANCEBLOCK Advance Block
CDLBELTHOLD Belt-hold
CDLBREAKAWAY Breakaway
CDLCLOSINGMARUBOZU Closing Marubozu
CDLCONCEALBABYSWALL Concealing Baby Swallow
CDLCOUNTERATTACK Counterattack
CDLDARKCLOUDCOVER Dark Cloud Cover
CDLDOJI Doji
CDLDOJISTAR Doji Star
CDLDRAGONFLYDOJI Dragonfly Doji
CDLENGULFING Engulfing Pattern
CDLEVENINGDOJISTAR Evening Doji Star
CDLEVENINGSTAR Evening Star
CDLGAPSIDESIDEWHITE Up/Down-gap side-by-side white lines
CDLGRAVESTONEDOJI Gravestone Doji
CDLHAMMER Hammer
CDLHANGINGMAN Hanging Man
CDLHARAMI Harami Pattern
CDLHARAMICROSS Harami Cross Pattern
CDLHIGHWAVE High-Wave Candle
CDLHIKKAKE Hikkake Pattern
CDLHIKKAKEMOD Modified Hikkake Pattern
CDLHOMINGPIGEON Homing Pigeon
CDLIDENTICAL3CROWS Identical Three Crows
CDLINNECK In-Neck Pattern
CDLINVERTEDHAMMER Inverted Hammer
CDLKICKING Kicking
CDLKICKINGBYLENGTH Kicking - bull/bear determined by the longer marubozu
CDLLADDERBOTTOM Ladder Bottom
CDLLONGLEGGEDDOJI Long Legged Doji
CDLLONGLINE Long Line Candle
CDLMARUBOZU Marubozu
CDLMATCHINGLOW Matching Low
CDLMATHOLD Mat Hold
CDLMORNINGDOJISTAR Morning Doji Star
CDLMORNINGSTAR Morning Star
CDLONNECK On-Neck Pattern
CDLPIERCING Piercing Pattern
CDLRICKSHAWMAN Rickshaw Man
CDLRISEFALL3METHODS Rising/Falling Three Methods
CDLSEPARATINGLINES Separating Lines
CDLSHOOTINGSTAR Shooting Star
CDLSHORTLINE Short Line Candle
CDLSPINNINGTOP Spinning Top
CDLSTALLEDPATTERN Stalled Pattern
CDLSTICKSANDWICH Stick Sandwich
CDLTAKURI Takuri (Dragonfly Doji with very long lower shadow)
CDLTASUKIGAP Tasuki Gap
CDLTHRUSTING Thrusting Pattern
CDLTRISTAR Tristar Pattern
CDLUNIQUE3RIVER Unique 3 River
CDLUPSIDEGAP2CROWS Upside Gap Two Crows
CDLXSIDEGAP3METHODS Upside/Downside Gap Three Methods
BETA Beta
CORREL Pearson's Correlation Coefficient (r)
LINEARREG Linear Regression
LINEARREG_ANGLE Linear Regression Angle
LINEARREG_INTERCEPT Linear Regression Intercept
LINEARREG_SLOPE Linear Regression Slope
STDDEV Standard Deviation
TSF Time Series Forecast
VAR Variance
ACOS Vector Trigonometric ACos
ASIN Vector Trigonometric ASin
ATAN Vector Trigonometric ATan
CEIL Vector Ceil
COS Vector Trigonometric Cos
COSH Vector Trigonometric Cosh
EXP Vector Arithmetic Exp
FLOOR Vector Floor
LN Vector Log Natural
LOG10 Vector Log10
SIN Vector Trigonometric Sin
SINH Vector Trigonometric Sinh
SQRT Vector Square Root
TAN Vector Trigonometric Tan
TANH Vector Trigonometric Tanh
ADD Vector Arithmetic Add
DIV Vector Arithmetic Div
MAX Highest value over a specified period
MAXINDEX Index of highest value over a specified period
MIN Lowest value over a specified period
MININDEX Index of lowest value over a specified period
MINMAX Lowest and highest values over a specified period
MINMAXINDEX Indexes of lowest and highest values over a specified period
MULT Vector Arithmetic Mult
SUB Vector Arithmetic Substraction
SUM Summation
Documentation Index


isambard.tools.file_parsing module¶
-
dict_from_mmcif
(mmcif, path=True)[source]¶ Parse mmcif file into a dictionary.
Notes
- Full list of keys/value types, and further information on them can be viewed here:
- http://mmcif.wwpdb.org/docs/pdb_to_pdbx_correspondences.html
All values in the returned dict are str or list(str). This means that some of the data values are string representations of integers - parse these outside of this function if desired. An alternative approach to this can be found in Biopython (via the function Bio.PDB.MMCIF2Dict.MMCIF2Dict). mmcif files are subject to the usual “here be dragons” problems of the PDB and difficult file formats. As such, this function is likely to be in a permanent state of flux as more dragons are found.
Parameters: Returns: cif_data – Keys are cif data names, e.g. ‘_struct_keywords.text’. Values are str or list(str).
Return type:
-
download_decode
(URL, encoding='utf-8', verbose=True)[source]¶ Downloads data from URL and returns decoded contents.
-
get_protein_dict
(cif_data)[source]¶ Parse cif_data dict for a subset of its data.
Notes
cif_data dict contains all the data from the .cif file, with values as strings. This function returns a more ‘human readable’ dictionary of key-value pairs. The keys have simpler (and still often more descriptive!) names, and the values are not restricted to being strings. To add more key-value pairs to the protein_dict, follow the patterns used in this function. Add the key and youre name for it to mmcif_data_names. Will it need further parsing, like with the dates in the function below? If the value is not a string, add it to a list of data-types at the end of the function. More information on what key-value pairs can be obtained can be gleaned by examining cif_data and/or by viewing the mmcif resource on the PDB website: http://mmcif.wwpdb.org/docs/pdb_to_pdbx_correspondences.html WARNING: Do not alter the keys of protein_dict without caution. The keys of protein_dict MUST match the column names of the Protein model in the protgraph database.
Parameters: cif_data (dict) – Key/value pairs taken directly from a .cif file. Output of the function dict_from_mmcif. Returns: protein_dict – A dictionary containing a parsed subset of the data in cif_data. The keys have the same name as fields in the Protein model. Return type: dict
-
olderado_best_model
(pdb_id)[source]¶ Checks the Olderado web server and returns the most representative conformation for PDB NMR structures.
Notes
Uses OLDERADO from the EBI. See http://www.ebi.ac.uk/pdbe/nmr/olderado/ and citations therein.
Parameters: pdb_id (str) – The 4-character PDB code for the NMR structure of interest. Returns: model_no – The conformation number of the most-representative conformation. Return type: int Raises: ValueError
– If the model number it finds is not an integer. This might indicate that the website format has changed.
-
parse_PISCES_output
(pisces_output, path=False)[source]¶ Takes the output list of a PISCES cull and returns in a usable dictionary.
Notes
Designed for outputs of protein sequence redundancy culls conducted using the PISCES server. http://dunbrack.fccc.edu/PISCES.php G. Wang and R. L. Dunbrack, Jr. PISCES: a protein sequence culling server. Bioinformatics, 19:1589-1591, 2003.
Parameters: Returns: pisces_dict – Data output by PISCES in dictionary form.
Return type:


For taking input a line of words with spaces in between them, we use getline which works a s follows:
string messageVar;
getline(cin, messageVar);
For taking input from a file instead of from the terminal using "cin" we can use ifstream as follows:
int x;
ifstream myfile;
myfile.open("input.txt");
myfile >> x;
myfile.close();


|
mlpack
1.0.12
|
This is not an actual space tree but instead an example tree that exists to show and document all the functions that mlpack trees must implement. More...
Public Member Functions | |
| ExampleTree (const MatType &dataset, MetricType &metric) | |
| This constructor will build the tree given a dataset and an instantiated metric. More... | |
| void | Centroid (arma::vec ¢roid) const |
| Fill the given vector with the center of the node. More... | |
| const ExampleTree & | Child (const size_t i) const |
| Return a particular child of this node. More... | |
| ExampleTree & | Child (const size_t i) |
| Modify a particular child of this node. More... | |
| size_t | Descendant (const size_t i) const |
| Get the index of a particular descendant point. More... | |
| double | FurthestDescendantDistance () const |
| Get the distance from the center of the node to the furthest descendant point of this node. More... | |
| double | MaxDistance (const MatType &point) const |
| Return the maximum distance between this node and a point. More... | |
| double | MaxDistance (const ExampleTree &other) const |
| Return the maximum distance between this node and another node. More... | |
| const MetricType & | Metric () const |
| Get the instantiated metric for this node. More... | |
| MetricType & | Metric () |
| Modify the instantiated metric for this node. More... | |
| double | MinDistance (const MatType &point) const |
| Return the minimum distance between this node and a point. More... | |
| double | MinDistance (const ExampleTree &other) const |
| Return the minimum distance between this node and another node. More... | |
| size_t | NumChildren () const |
| Return the number of children of this node. More... | |
| size_t | NumDescendants () const |
| Get the number of descendant points. More... | |
| size_t | NumPoints () const |
| Return the number of points held in this node. More... | |
| ExampleTree * | Parent () const |
| Return the parent node (NULL if this is the root of the tree). More... | |
| double | ParentDistance () const |
| Get the distance from the center of this node to the center of the parent node. More... | |
| size_t | Point (const size_t i) const |
| Return the index of a particular point of this node. More... | |
| math::Range | RangeDistance (const MatType &point) const |
| Return both the minimum and maximum distances between this node and a point as a math::Range object. More... | |
| math::Range | RangeDistance (const ExampleTree &other) const |
| Return both the minimum and maximum distances between this node and another node as a math::Range object. More... | |
| const StatisticType & | Stat () const |
| Get the statistic for this node. More... | |
| StatisticType & | Stat () |
| Modify the statistic for this node. More... | |
Private Attributes | |
| MetricType & | metric |
| This member is just here so the ExampleTree compiles without warnings. More... | |
| StatisticType | stat |
| This member is just here so the ExampleTree compiles without warnings. More... | |
This is not an actual space tree but instead an example tree that exists to show and document all the functions that mlpack trees must implement.
For a better overview of trees, see trees. Also be aware that the implementations of each of the methods in this example tree are entirely fake and do not work; this example tree exists for its API, not its implementation.
Note that trees often have different properties. These properties are known at compile-time through the mlpack::tree::TreeTraits class, and some properties may imply the existence (or non-existence) of certain functions. Refer to the TreeTraits for more documentation on that.
The three template parameters below must be template parameters to the tree, in the order given below. More template parameters are fine, but they must come after the first three.
| MetricType | This defines the space in which the tree will be built. For some trees, arbitrary metrics cannot be used, and a template metaprogramming approach should be used to issue a compile-time error if a metric cannot be used with a specific tree type. One example is the tree::BinarySpaceTree tree type, which cannot work with the metric::IPMetric class. |
| StatisticType | A tree node can hold a statistic, which is sometimes useful for various dual-tree algorithms. The tree itself does not need to know anything about how the statistic works, but it needs to hold a StatisticType in each node. It can be assumed that the StatisticType class has a constructor StatisticType(const ExampleTree&). |
| MatType | A tree could be built on a dense matrix or a sparse matrix. All mlpack trees should be able to support any Armadillo-compatible matrix type. When the tree is written it should be assumed that MatType has the same functionality as arma::mat. |
Definition at line 58 of file example_tree.hpp.
| mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::ExampleTree | ( | const MatType & | dataset, |
| MetricType & | metric | ||
| ) |
This constructor will build the tree given a dataset and an instantiated metric.
Note that the parameter is a MatType& and not an arma::mat&. The dataset is not modified by the tree-building process (if it is, see the documentation for mlpack::tree::TreeTraits::RearrangesDataset for how to deal with that situation). The MetricType parameter is necessary even though some metrics do not hold any state. This is so that the tree does not have to worry about instantiating the metric (if the tree had to worry about this, this would almost certainly incur additional runtime complexity and a larger runtime size of the tree node objects, which is to be avoided). The metric can't be const, in case MetricType::Evaluate() is non-const.
When this constructor is finished, the entire tree will be built and ready to use. The constructor should call the constructor of the statistic for each node that is built (see tree::EmptyStatistic for more information).
| dataset | The dataset that the tree will be built on. |
| metric | The instantiated metric to use to build the dataset. |
| void mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::Centroid | ( | arma::vec & | centroid | ) | const |
Fill the given vector with the center of the node.
| centroid | Vector to be filled with the center of the node. |
| const ExampleTree& mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::Child | ( | const size_t | i | ) | const |
Return a particular child of this node.
| ExampleTree& mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::Child | ( | const size_t | i | ) |
Modify a particular child of this node.
| size_t mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::Descendant | ( | const size_t | i | ) | const |
Get the index of a particular descendant point.
The ordering of the descendants does not matter, as long as calling Descendant(0) through Descendant(NumDescendants() - 1) will return the indices of every unique descendant point of the node.
| double mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::FurthestDescendantDistance | ( | ) | const |
Get the distance from the center of the node to the furthest descendant point of this node.
This does not necessarily need to be the exact furthest descendant distance but instead can be an upper bound. See the definitions in trees for more information.
| double mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::MaxDistance | ( | const MatType & | point | ) | const |
Return the maximum distance between this node and a point.
It is not required that the exact maximum distance between the node and the point is returned but instead an upper bound on the maximum distance will suffice. See the definitions in trees for more information.
| point | Point to return [upper bound on] maximum distance to. |
| double mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::MaxDistance | ( | const ExampleTree< MetricType, StatisticType, MatType > & | other | ) | const |
Return the maximum distance between this node and another node.
It is not required that the exact maximum distance between the two nodes be returned but instead an upper bound on the maximum distance will suffice. See the definitions in trees for more information.
| node | Node to return [upper bound on] maximum distance to. |
| const MetricType& mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::Metric | ( | ) | const |
Get the instantiated metric for this node.
| MetricType& mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::Metric | ( | ) |
Modify the instantiated metric for this node.
| double mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::MinDistance | ( | const MatType & | point | ) | const |
Return the minimum distance between this node and a point.
It is not required that the exact minimum distance between the node and the point is returned but instead a lower bound on the minimum distance will suffice. See the definitions in trees for more information.
| point | Point to return [lower bound on] minimum distance to. |
| double mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::MinDistance | ( | const ExampleTree< MetricType, StatisticType, MatType > & | other | ) | const |
Return the minimum distance between this node and another node.
It is not required that the exact minimum distance between the two nodes be returned but instead a lower bound on the minimum distance will suffice. See the definitions in trees for more information.
| node | Node to return [lower bound on] minimum distance to. |
| size_t mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::NumChildren | ( | ) | const |
Return the number of children of this node.
| size_t mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::NumDescendants | ( | ) | const |
Get the number of descendant points.
This is the number of unique points held in this node plus the number of points held in all descendant nodes. This could be calculated at build-time and cached, or could be calculated at run-time. This may be harder to calculate for trees that may hold points in multiple nodes (like cover trees and spill trees, for instance).
| size_t mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::NumPoints | ( | ) | const |
Return the number of points held in this node.
| ExampleTree* mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::Parent | ( | ) | const |
Return the parent node (NULL if this is the root of the tree).
| double mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::ParentDistance | ( | ) | const |
Get the distance from the center of this node to the center of the parent node.
| size_t mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::Point | ( | const size_t | i | ) | const |
Return the index of a particular point of this node.
mlpack trees do not, in general, hold the actual dataset, and instead just hold the indices of the points they contain. Thus, you might use this function in code like this:
| math::Range mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::RangeDistance | ( | const MatType & | point | ) | const |
Return both the minimum and maximum distances between this node and a point as a math::Range object.
This overload is given because it is possible that, for some tree types, calculation of both at once is faster than a call to MinDistance() then MaxDistance(). It is not necessary that the minimum and maximum distances be exact; it is sufficient to return a lower bound on the minimum distance and an upper bound on the maximum distance. See the definitions in trees for more information.
| point | Point to return [bounds on] minimum and maximum distances to. |
| math::Range mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::RangeDistance | ( | const ExampleTree< MetricType, StatisticType, MatType > & | other | ) | const |
Return both the minimum and maximum distances between this node and another node as a math::Range object.
This overload is given because it is possible that, for some tree types, calculation of both at once is faster than a call to MinDistance() then MaxDistance(). It is not necessary that the minimum and maximum distances be exact; it is sufficient to return a lower bound on the minimum distance and an upper bound on the maximum distance. See the definitions in trees for more information.
| node | Node to return [bounds on] minimum and maximum distances to. |
| const StatisticType& mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::Stat | ( | ) | const |
Get the statistic for this node.
| StatisticType& mlpack::tree::ExampleTree< MetricType, StatisticType, MatType >::Stat | ( | ) |
Modify the statistic for this node.
|
private |
This member is just here so the ExampleTree compiles without warnings.
It is not required to be a member in every type of tree. Be aware that storing the metric as a member and not a reference may mean that for some metrics (such as metric::MahalanobisDistance in high dimensionality) may incur lots of unnecessary matrix copying.
Definition at line 236 of file example_tree.hpp.
|
private |
This member is just here so the ExampleTree compiles without warnings.
It is not required to be a member in every type of tree.
Definition at line 227 of file example_tree.hpp.


As this tutorial is on table joins lets pull in this information from the IBM's DB2 information center. To do this a 'pageWindow' menu element is used. There are a few things different about this menu from the one that was used earlier. Fist there is no primary panel set so the 'title' element has been used within the 'pageWindow' element to set a tab title. Next within the panel in place of the 'link' element the 'URL' element has been used and it contains a HTML URL which will be loaded in an iframe embedded within the panel.
Impotent note: When importing links from the information center if you do not wish the entire information center to load but just the page you are interested loaded, add the following '?noframes=true' to the end of the URL.
Steps to complete:


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Scala has support of algebraic data types out of the box but often it is not enough for complex cases.
In this article I will try to show its limits and how to bypass them using shapeless
library by the example of sum data types
.
Scala has support of algebraic data types out of the box but often it is not enough for complex cases.
In this article I will try to show its limits and how to bypass them using shapeless
library by the example of sum data types
.
In the previous article we discussed usage of hll countes for finding the number of unique values in a collection. But in this article we will see how to use them in Cassandra db internally in order to provide such functionality using user defined functions(UDF) and aggregates(UDA).
Type variance in scala is quite a tricky topic especially if you do not use it often - details might slip out of mind easily in this case. So below you can find very short tips about it which purpose is to remind how it works.
In this article we will see how to use different streams(like akka-stream) for pagination and when it can be useful. The main idea of pagination is partition of a big sequence of objects into several parts(or pages) in order to make possible its processing page by page. For example, you have a 1.000.000 users in the database and you need to send an email to all of them. You could try to load all user records in a big list and process it at once but it would not be memory-efficient approach. Instead you can partition the list of users into pages by 100 users per page, load one page, send emails to users in this page, load next page and so on. This will be a much more efficient way to deal with big collections of records.
So lets try to implement this approach but for a more complex case.
This article is about possible solutions for validation in scala. Validation is the process of checking input data in order to provide its correctness and requirements compliance.
There are several libraries in scala which can be used for validation:
The source code for this article is here
In this article you can find information about using t-digest
library in order to measure average value of some quantity(average session time).
There is also an answer for the question: What and why should you use to make such the measurement mean or median?
Besides, list and comparison of different implementations is presented below in the article.
So in what cases we have need to calculate mean/median? For example we have a site and we want to understand how much time an average user spent on our site. In order to do it we should calculate an average duration of a user session. And there are at least two ways to do it - calculate an arithmetic mean(or just mean) or calculate a median. The calculation of mean is very simple. You need two fields: one for a sum of elements and another for their count. But it doesn`t work very well with anomalies in the data. I mean the case when one or several elements differ greatly from others. Lets assume that we have such values for our session durations(in milliseconds):
3000, 2000, 3000, 5000, 3000, 4000, 4500, 3200, 2700, 3380
mean = (3000+2000+3000+5000+3000+4000+4500+3200+2700+3380) / 10 = 3378 msecs
. In this case all is ok.
But what if one of these users opens the site, forgets to close a browser tab and goes afk for an hour(3.600.000 msecs):
3000, 2000, 3000, 5000, 3000, 4000, 4500, 3200, 2700, 3600000
mean = (3000+2000+3000+5000+3000+4000+4500+3200+2700+3600000) / 10 = 363040 msecs
. Just one of the users influences strongly on mean value.
Generally speaking, the mean is only representative if the distribution of the data is symmetric, otherwise it may be heavily influenced by outlying measurements.
In simple cases it is possible to use some kind of a filter.
But often we just don’t know what threshold we should use to filter values.
Whereas the median value is the same in both cases and is equal to 3100
. So in the cases like this the median will be more useful then the mean.
However the calculation of the median in general case needs a lot of memory - O(n)
In this article we will look at HLL algorithm and different implementations of it.
HLL is a propabalistic algorithm which is used for a estimation of unique values. More details about HLL you can get here. The main reason to use HLL is necessity to estimate uniques in very big amount of data in case if it is possible to sacrifice accuracy of an unique counter.
You can find several implementations of HLL:
Next in this article we will take a close look at all these libs and answer the question: «Why should we use HLL?».
In this article let’s take a look at such a thing as lens(or lenses). A Lens is an abstraction from functional programming which helps to deal with a problem of updating complex immutable nested objects like this:
case class User(id: UserId, generalInfo: GeneralInfo, billInfo: BillInfo)
case class UserId(value: Long)
case class GeneralInfo(email: Email,
password: String,
siteInfo: SiteInfo,
isEmailConfirmed: Boolean = false,
phone: String,
isPhoneConfirmed: Boolean = false)
case class SiteInfo(alias: String, avatarUrl: String, userRating: Double = 0.0d)
case class Email(value: String)
case class BillInfo(addresses: Seq[Address], name: Name)
case class Name(firstName: String, secondName: String)
case class Address(country: Country, city: City, street: String, house: String, isConfirmed: Boolean = false)
case class City(name: String)
case class Country(name: String)
If we want to increase userRating
in this model then we will have to write such a code:
val updatedUser = user.copy(
generalInfo = user.generalInfo.copy(
siteInfo = user.generalInfo.siteInfo.copy(
userRating = user.generalInfo.siteInfo.userRating + 1
)
)
)
And we have to write the code below to confirm all of the addresses in BillInfo
val updatedAddresses = user.billInfo.addresses.map(_.copy(isConfirmed = true))
val updatedUser = user.copy(
billInfo = user.billInfo.copy(addresses = updatedAddresses)
)
If we increase a level of nesting in our structures then we will considerably increase amount of a code like this. In such cases lens give a cleaner way to make changes in nested structures.
How it was said in the previous article there is no way to do truly fail-fast async error handling using only scala or scalaz.
Look at the example below:
val longFut = longFuture() // very long future
val shortFut = shortFuture()
val failedFut = failedFuture() // throw new IllegalStateException("future is failed")
val result = for {
long <- longFut
short <- shortFut
failed <- failedFut
} yield {
long + " | " + short + " | " + failed
}
In that example we will wait all the futures until we get IllegalStateException
because for-comprehension
always handle futures in the order which we define them since Scala translates the example above to this:
longFut.flatMap { long =>
shortFut.flatMap { short =>
failedFut.map { failed =>
long + " | " + short + " | " + failed
}
}
}
But it is possible to avoid this problem with Expression library(link)
Many of us know about such library as scalaz. For those who don’t know it is a library for functional programming in scala. You can find it here. Then I was trying to learn and understand this lib it was quite difficult to realize how exactly it can be used in a real code in a real system. I looked thought lots of articles about it, but there were only abstract examples. So I`ve decided to write a little example in order to show how scalaz can be used in a real system.
Idea: Future and scalaz.Either can be used as a result of an asynchronous operation.
Reason: We must compose futures and eithers in order to deal with possible errors which may occur during execution of async operations.
For example we have to gather information from several different DBs and an external service like Twitter. We also don`t want to use exceptions as notifications about errors. Why? Because it sucks ^_^ It will be better if exceptions are used for something really exceptional. One more thing which we should implement is fail-fast error handling because it will be wasteful to continue program execution if it already contains some errors.


The LanguageFontGroup API should not be confused with a font fallback mechanism. It provides a single font recommendation for a given language, and the assumption is that the text formatted with that font is all in that language. If the content does happen to contain text in another language that that font does not support, then application frameworks provided by Windows will automatically apply a fallback font to those portions of the text when it is rendered. The typographic quality may be less than optimal, however. This shows a comparison of a single font for English being applied to mixed English/Japanese text versus separate recommended fonts being applied to English text and Japanese text.
Lorem ipsum dolor sit amet, ne 訧焨を餯ダ 拣饵廦え尤 栧穃榞しゃぴゃ 餯ダ ら横襩 ペ覧へ iisque interpretaris sit. Ex sea maluisset urbanitas adolescens, id porro constituto percipitur vis, mucius ridens liberavisse has at.
Lorem ipsum dolor sit amet, ne 訧焨を餯ダ 拣饵廦え尤 栧穃榞しゃぴゃ 餯ダ ら横襩 ペ覧へ iisque interpretaris sit. Ex sea maluisset urbanitas adolescens, id porro constituto percipitur vis, mucius ridens liberavisse has at.


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| Select your board to see available online firmware releases - Select the correct firmware appropriate for your board | |
| Select firmware version for your board. | |
| Enable if you powered your FC while the bootloader pins are jumpered or have your FC's BOOT button pressed. | |
| Attempt to flash the board automatically (triggered by newly detected serial port). | |
| Wipes all configuration data currently stored on the board. | |
| Manual selection of baud rate for boards that don't support the default speed or for flashing via bluetooth. Note: Not used when flashing via USB DFU |
|
| Show Release-Candidates and Development Releases. |


Whether your vision is that of a intimate boutique or a bigger-than-life shopping experience, my work will enhance and emphasize the spirit of your brand.
The latest tools and technologies in design and safety, balanced with a welcoming sense of familiarity will be combined in order to give your website the ultimate user-experience.
Keep track of your business long term with a standalone admin interface, ideal for adding and modifying stock as well as managing your mailing list and blog posts.
(Soon to be) Fullstack Developer
I've discovered my interest in code through my love for design and aesthetic! As I found myself fascinated by the many aspects of coding and developing web environments I've decided to pursue this new direction and enrolled in Coding Academy.


Shortening OLC codes
OLC codes are a bit like an address - if you know that they are near something, you can drop some of the characters.
Click on the map to see the steps in shortening a code. Or enter the final part of a code and a place below to see how the original code is recovered.


Add an extra layer of protection to Twilio accounts. Once you enable 2FA, all users accessing this account must enter verification codes sent on the channel they prefer. To enable 2FA for yourself, go to User Settings.
Determines if certificate validation is performed on all Twilio originated requests.
Public Key Client Validation provides an additional layer of security by validating the origin and integrity of the request being sent to Twilio. This is achieved by sharing a public key with Twilio and then signing each request with the associated private key.
This will generate a secondary auth token for use as a backup or during key rotation.
Careful. Promoting this token means that the primary token will be deleted and any subsequent API requests using that token will fail.
Careful. Deleting this token means that any API requests using this token will fail.


Recipe 14.8. Authenticating with a Proxy for HTTPS Navigation
Credit: John Nielsen
Problem
You need to use
httplib for HTTPS navigation through a proxy that
requires basic authentication, but httplib out of
the box supports HTTPS only through proxies that do
not require authentication.
Solution
Unfortunately, it takes a wafer-thin amount of trickery to achieve
this recipe's task. Here is a script that is just
tricky enough:
import httplib, base64, socket
# parameters for the script
user = 'proxy_login'; passwd = 'proxy_pass'
host = 'login.yahoo.com'; port = 443
phost = 'proxy_host'; pport = 80
# setup basic authentication
user_pass = base64.encodestring(user+':'+passwd)
proxy_authorization = 'Proxy-authorization: Basic '+user_pass+'\r\n'
proxy_connect = 'CONNECT %s:%s HTTP/1.0\r\n' % (host, port)
user_agent = 'User-Agent: python\r\n'
proxy_pieces = proxy_connect+proxy_authorization+user_agent+'\r\n'
# connect to the proxy
proxy_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
proxy_socket.connect((phost, pport))
proxy_socket.sendall(proxy_pieces+'\r\n')
response = proxy_socket.recv(8192)
status = response.split( )[1]
if status!='200':
raise IOError, 'Connecting to proxy: status=%s' % status
# trivial setup for SSL socket
ssl = socket.ssl(proxy_socket, None, None)
sock = httplib.FakeSocket(proxy_socket, ssl)
# initialize httplib and replace the connection's socket with the SSL one
h = httplib.HTTPConnection('localhost')
h.sock = sock
# and finally, use the now-HTTPS httplib connection as you wish
h.request('GET', '/')
r = h.getresponse( )
print r.read( )
Discussion
HTTPS is essentially HTTP spoken on top of an SSL connection rather
than a plain socket. So, this recipe connects to the proxy with basic
authentication at the very lowest level of Python socket programming,
wraps an SSL socket around the proxy connection thus secured, and
finally plays a little trick under
httplib's nose to use that
laboriously constructed SSL socket in place of the plain socket in an
HTTPConnection instance. From that point onwards,
you can use the normal httplib approach as you
wish.
See Also
Documentation on the socket and
httplib standard library modules in the
Library Reference and Python in a
Nutshell.
|


Make your scientific Python 3 code reproducible by deterministic hashing
03 Jan 2016
As of Python 3.3, the built in hash
function is randomized by default – for very good reasons! In short, having a deterministic hash function in production code is quite a security risk. We can see the effect of a randomized hash function by outputting the content of a set on multiple runs:
python -c "print(set(['A','B','C']))"
{'A', 'C', 'B'}
python -c "print(set(['A','B','C']))"
{'B', 'C', 'A'}
For scientific code, though, this could potentially be a problem. Since we want to make sure our work is as reproducible as possible, any stochastic elements will potentially make it difficult to regenerate previous experimental results.
As an example, I have some code that outputs a dictionary of features in the following format:
Number=Sing|Definite=Ind|Gender=Com|Case=Nom
The problem appears whenever I rerun the output and want to see if any differences arise between runs. Since the order of the dictionary output is determined by the hashing of the original keys, I cannot use e.g. git diff
to compare the previous commited output with the current one.
If you have complete control and knowledge of your environment, your best bet is to either use OrderedDict
and its counterparts whenever the sorting order cannot be assumed, or to simply sort the items of your dictionary ahead of iteration.
Most of the time, we don’t have this luxury. I quite often rely upon separate libraries and scripts for my work that I cannot in good faith start modifying. Instead, we could ahead of running the experiments set the environment variable PYTHONHASHSEED
to an integer value.
export PYTHONHASHSEED=0
python run_experiment.py
At last, I want to emphasize: this should only be done with the purpose of having a non-random ordering of sets and dictionaries! If you actually want a deterministic hash value of e.g. a string, you should almost always use hashlib.


My Portfolio
My Portfolio
My Portfolio
My Portfolio
My Portfolio
My Portfolio
This is my portfolio. My name is gagan.
I am 20 years old
Click here to get a random message:
GaganThis is my portfolio. My name is gagan.
I am 20 years old
Click here to get a random message:
Gagan


DNS Configuration
Nov 2, 2017 00:40 · 357 words · 2 minutes read
One of the biggest challenges around DNS configuration for a less-technical internet end-user is exactly that, the word DNS itself. Most people are not going to understand what DNS is and why would it even matter to them. To the less-technical internet end-user, they aren’t going to bother learning about this and when you speak to them about it, they are going to look at you like you are speaking another language. You are going to first have to define DNS in a simple way that they can understand. As such, DNS is the way your computer speaks to the website you are going to. Each website such as www.facebook.com is actually a bunch of numbers to the computer such as 1010101 or <IP_ADDRESS> and it will translate it for you to wwww.facebook.com so you can go to that website. If the DNS is not working you will get an error page.
The second biggest challenge is how do you even configure it and why would you configure it. If most people don’t know a DNS is or what it is meant for, they aren’t going to know how to configure it and why they should. Explain to them that the DNS configuration will make a webpage load faster. Though then we get into the issue of having them configure it which will be another issue itself because you will have to walk them through it step by step. Such as right clicking on their internet icon going to Network and Sharing Center clicking on Ethernet (or Wireless) under Connection, from that dialogue box clicking properties (if another dialogue box pops up click okay), going to Internet Protocol Version 4 (TCP/IPv4) and clicking properties going to the area that says “Obtain DNS server adddress automatically” to clicking “Use the following DNS server addresses” and inputing the DNS servers you can find on both Google DNS or Open DNS (which I will link below)
https://developers.google.com/speed/public-dns/
Open DNS actually has a step by step guide for each OS and even routers. You must remind them that they cannot just randomly put in numbers and expect them to work.


Schedul҉i͠ng̸ for 2 hours bu҉t҉ sh͢o҉u̵l̕d only ҉t̸a͠ke ͞a few minutes
We'͜ĺl̴ ̵be̛ ̸givin̷g͟ ̕ţim̡e ̵back
U͔͇̮͚̙̮̣̖͖ͯ͒̓̋ͪn̨͇̜̱͚̰̻̔͌̾̌̽͌̈i̡̠̹̯͓͇̯͕̮̬ͪ̒͊̽̓ͫ̓̆ͦc͎̰ͣ͒̓̒͗̒̆́ͅo̶͚̖͇̗ͯ̇ͣ̾̓̇ḑ̧̪͍͚͋͂̀͒̀̚ͅe̷̝͉̱̤͑͑̐̿̕ ̝̼̜̙͖̱̤͍̱̐̒̽̐ͣ͋͝ï̛̹̮̯̥̔̓͐̓ͮ̕͡s͕̼͕̓̀̋n̷̦͉̦̣̉̆̇ͪ͒ͩ͠'̢̘̱͙̈̈̂̌̃͐͒t̻̖̲̍ͨͭͧ̓̀̅̿̍͡ͅ ̷̵̟͎ͪ͌͂͌ͩͮ̉̚͡r͎̲̝̝̊͆͒ͫ̎̈ȩ͔̪̠̦̗͋̈̒̀͒̽ͨͤ͢͡ä̼͕̥͉̰͚̲͊͊̍̀l̻̳͈̫̠̟̾́̏̚͢ľͬ̍ͭ͋̑̀҉̰̙̹̺y̶̡̖͍͕͖̦̝̤̝ͩͩͯ̋̎͆́́ͩ ̲̠̤̳̗͔̠̰ͫ̽̇͒͛t̶̠̟̘̞̘͉̲̉̃ͥ̇̇̐̅̄h̸̭̰̜͚̞̳̦̮̾ͤ͂̄̀͝a̜̼̬̰̋͆͒̇̈ţ͕̪̻͉̱̽́̽͑ͣ̇͒͊ͪ ̖̫͈̤͚̗̈́̅ͦ́͢͡c͍̉͡͠õ̸̘̩̣͙̬ͫ̊̅͛̍͐ͮ͜m̶̨̲̹̠̜͕̿͠p͚̗͍͖̦͕̑̃͋̄́ͅlͯ͐͛̃̇̉͌҉̨̧̳͇̩͉͚̞ͅͅͅę̶͖͇̦̤̩̳̹͛̽͝x̴̥̜͈̟͓͓͛̓̓̂̐̑̏̍͘ ̷̖̲̌́ͩȯ̷̢̠̂ͪ̾̋̏f̵̥͐̄͊ ͎̣͓̯͎̜̻̐̌̉a̸̲̹̽ͯͦ̌͑̾̓̎ ̴̻̦̝̠̆̑̏̔̂̀̋̀̕t̝̤͉̪̺͕̪̦̑̒ͫ͛̈ͨ́o̯̗̖͓̥̩̓̔ͦp̺̦̝̞̪̤̗̮̣͑ͫ̋ͥ͜i̪̯͕͊̀̂ͫ̐̍̀ç̨̜̀̓̽́͋̓̓ͨ̚͡ ̺̗̈̓͘a̢̳̜̮̫͂n̪̯ͪ̿̑͌ͧ̒ͧ͆ẏ̶̠͚̤̊͊ͣ̚͠͝w̖͔͔̤̗̜̆̐͂͒̎̑́̑͝a̘̯͈̻̥͍̺ͮͅͅy̦̺̰͕͖͉ͨͦ̇̓͞͞ͅ
A font is a mapping of characters to glyphs.
It's a giant table of bitmaps or vectors
that represent characters.
A glyph is a visual representation of a character.
A font can contain many glyphs for the same character with multiple styles.
Ok, but how do you tell the font which glyph you want?
Unicode is an international standard for
representing and working with text
It covers the majority of Earth's writing systems
It includes 283,506 characters as of Version 13
Unicode is also a giant table,
except it holds code points
A code point is an integer assigned to a character.
Often written like U+XXXX
| Code Point | Name | Block | Glyph |
|---|---|---|---|
| U+0007 | BELL | Control Characters | (none) |
| U+0041 | LATIN CAPITAL LETTER A | Basic Latin | A |
| U+13A3 | CHEROKEE LETTER O | Cherokee | Ꭳ |
| U+030C | COMBINING CARON | Combining Diacritical Marks | ◌̌ |
A grapheme is a combination of one or more code points that represent an atomic unit of a particular writing system
"Character" is ambiguous and the term should be avoided when talking about text.
Use code point when referring to an entry in the Unicode database
Use grapheme when referring to an atomic unit of a writing system (letter, punctuation, or emoji)
Use glyph when referring to a particular visual representation of a grapheme
Ok but how do you represent any of this in computer memory 😣
Bwaaamp?


Installation complete!
data is now installed in your system. To see a list of available commands, open a terminal and enter:
> data
You're now able to install all the datadex datasets from the commandline. For example, to get the MNIST dataset, run:
> data get jbenet/mnist
Find datasets and more informaton at http://datadex.io, or in these documents:


- URL{{url}}
- DDP status{{ddp}} {{reason}}
- Device ID{{deviceid}}
{{#each syncers}}
- {{name}} sync status{{syncStatus}}
- {{name}} sync time {{syncTime}} ms
- {{name}} sync date{{syncDate}}
{{/each}}
{{> tos_text}}
Choose the locations you'd like to view jobs and send messages to. Selections here don't affect what notifications you receive.
{{#each locations}}
{{> settings_locations_location}}
{{/each}}
{{name}} ({{code}}){{#if enabled}}✓{{else}}✕{{/if}}
Choose the locations for which you'd like to receive job notifications for.
{{#each locations}}
{{> settings_notifications_location}}
{{/each}}
{{name}} ({{code}}){{#if enabled}}✓{{else}}✕{{/if}}
Super!


{% extends "siem/base.html" %} {% block sub-title %} | Daemon Documentation{% endblock %} {% block content-main %}
LDSI includes a parse daemon to parse events, and a sentry daemon to monitor rules. In addition, it includes a cleaning utility that can be used to clean old log events. These are all managed using the start.sh script.
Usage: start.sh [-hv] <directory> <command> Optional arguments: -h Print this help message -v Print the version number -r Restart daemons -k Stop daemons -c Clean old events using backup EOL date -l Clean old events using local EOL date -b <ldsi-base> Set the LDSI base directory -e <env-base> Set a virtual environment
Daemons can be started manually, or by /etc/rc.local. Parser configuration is located in config/parser.conf inside the repository. Cleaning can be done manually, or by cron.
{% endblock %}


Burger
A hamburger is a type of sandwich made from grilled or grilled fillet meat, grilled or grilled, although it can also be fried or baked.Pizza
Pizza is a baked flatbread dough, usually round in shape, made from wheat flour, salt, water and yeast, topped with tomato sauce and cheese.Hot Dog
Hot dog is a sandwich-shaped food that is generated with the combination of a boiled or fried sausage of the Frankfurt sausage or Viennese type served in an elongated bread that is usually accompanied with some dressing, such as tomato sauce, mustard and onion.


Building Websites with Jekyll and GitHub pages
So you want to build a website...
- Blog
- Personal website
- Project website
- Static vs. Dynamic sites
What is Jekyll?
- A Ruby library (gem)...
- For autogenerating static websites...
- From content in either HTML or Markdown
Outline
- Create GitHub repository
- Make sure Ruby is installed
- Install Jekyll gem
- Create project directory
- Make some changes
- Commit to GitHub
Create GitHub repository
- Log in
- Create new...
- Notice the `remote master` line
- Project repo vs. User repo
- Make sure Ruby is installed...
- Install Jekyll library
First jekyll command
- jekyll new [directory-name]
- Directory name should be the same as your repo
name.
- Run jekyll serve
- Go to http://localhost:4000
Make some changes
- _config.yml
- index.html
- _posts/
Commit to GitHUb
- Add remote master
- git add .
- git commit -m 'initial commit'
- git push origin [master/branch]


About me
Tree view.
Introduction
Tree view with CSS and JavaScript. Thanks to
Learn how to create a tree view with CSS and JavaScript.
Canvas.
Example of including a canvas in the tree branch.


Lower Bounds Limits Plasma
Transcript By: Bryan Bishop
Tags: Layer 2
Category: Conference
Lower Bounds for Off-Chain Protocols: Exploring the Limits of Plasma
Stefan Dziembowski
https://twitter.com/kanzure/status/1230183338746335233
Introduction
Okay, thank you. The title of my talk is exploring the limits of plasma. This is joint work with others.
Plasma
Let me start by telling you about Plasma. It’s a family of layer 2 solutions for scaling blockchain. It was proposed in 2017 by Poon and Buterin. It’s a family of protocols. There’s plenty of different plasmas. This is a diagram from more than a year ago. There are many variants. It’s an active area, very chaotic.
Another name for this area is “commit chains”.
Our results formally
We prove that every plasma system must either have large exits (like Plasma Cash) or it must suffer from a mass exit problem caused by data unavailability. The paper is provided online at https://eprint.iacr.org/2020/175.
You cannot have the best of both worlds here.
Outline
Let me start by talking about how Plasma works. It can be thought of as a bank on the blockchain. You have an operator of the bank, and you have some people who have some tokens in the bank. It’s secured by the blockchain. The blockchain in the background secures the operations. The smart contract guarantees security.
The blockchain is the main chain, and then there’s the Plasma chain.
Actions for users
The users can add more tokens to the bank account, or withdraw tokens, or transfer tokens between users. It’s just like a bank.
Main design idea
The main design idea is that there’s an operator for the plasma contract on the main chain. The operator maintains a virtual ledger called a Plasma chain or Plasma ledger and he publishes this off-chain, on his webpage for example. He periodically hashes the contents of this plasma ledger into the main chain in a Plasma contract. The operator will hash everything and put it on the blockchain.
So there’s off-chain operations, and then on-chain operations for publishing.
The savings here are quite obvious. If you make many transactions between users, they don’t have to put them on chain, they just do it virtually on the operator’s webpage with the security guarantee that things are hashed.
This provides security agains tarbitrary corruptions, including a corrupt operator.
Some more details
So you have an operator and a user. The operator will hash the plasma ledger on the main chain and users… so merkle hashes are used for this so that every user can efficiently prove that his account was hashed into the merkle root and put it into the main chain. It’s required that every user constantly monitors the situation and provides some checks.
The user has to check that the plasma ledger was published off-chain, monitoring the operator’s website constantly. He has to check if what was published with at least what was on chain, so he checks the hash integrity. And then he checks that the ledger is “syntactically correct”.
If it doesn’t work, the user can prove that the operator is corrupt. It’s the responsibility of the user to watch everything.
A problem
If you look at the checks again, there’s a problem. If the hash is computed correctly, or the ledger is not syntactically correct, then I could prove it. But the problem is that if you check L was published at all off-chain… This is subjective. It cannot be proven or refuted. Non-publication cannot be refuted.
This is called a data unavailability attack. This happens when the publisher publishes the hash on the chain, but doesn’t publish the corresponding ledger on his webpage.
The problem is that this is subjective.
How to react to data unavailability?
The simplest solution to data unavailability is to take your money and run. If I can prove that there’s data unavailability, then I withdraw all my coins and go somewhere else.
Problems
Data unavailability is subjective, so it’s not clear who should pay the fees. If I’m escaping with all my money, there’s costs and then this could lead to “griefing” This could be called “non-uniquely attributable fault” because the smart contract can’t tell who is corrupt- either the user is misbehaving or the operator is.
Another problem is that with data unavailability, then you could have a situation called “mass exit” where everyone tries to exit at the same time.
Mass exits caused by data unavailability
Unfortunately, mass exit can cause blockchain congestion, which layer 2 was supposed to solve in the first place. So the question is, can we have a version of Plasma that doesn’t have mass exits caused by data unavailability?
Plasma Cash
The answer is yes, with Plasma Cash, which is based more on tokens than on users. So you have concept of tokens, that have owners, and they are not divisible, and they cannot be merged or divided. They are like “game items”. The nice thing about Plasma Cash is that there’s no mass exits, and no non-uniquely attributable faults.
How is this possible? Every token has an “owner”. Each user has to “protect” only her own tokens. The only thing the user has to do is watch if their own tokens are leaving the Plasma Cash.
This is called “non-fungible plasma”. The conventional one is fungible plasma, or normal plasma.
This comes at a price
In Plasma Cash, the exit size is linear in the number of tokens that the user withdraws. The amount of data that you can put on the main chain when withdrawing tokens is linear in the amount of money they have. So if I have some tokens, then I have to put on those exact tokens. It’s linear in the amount of money.
The consequence of this is that Plasma Cash cannot be converted to the fungible one by using very small denominations.
Plasma cash vs Fungible plasma
So what’s the difference between plasma cash and fungible plasma? Well, plasma cash has large exit size, but doesn’t have mass exits. Fungible plasma has short exit sizes, but it has mass exits.
For Plasma Cash one example is Loom Network. For fungible plasma, there’s NOCUST, OmiseGo, Matic, Bankex.
So the question is, is this inherent? Could we have no mass exits and small exit size at the same time? The main message of our paper is negatory: you can’t have that.
Recently in the past month, there were a lot of reports about data availability and plasma. …. This result confirms that this was not… it’s something inherent.
Our result
Let me tell you more about the technical part of the paper. An attacker in plasma… the adversary takes full control over corrupt users. The scenario is to ask how the honest users behave.
This is “mass forced on-chain action”- a situation when honest users need to quickly send a lot of data into the blockchain when they did not want to exit. IT’s almost the same as a mass exit, but it’s slightly more general.
Our theorem is that for every Plasma pi one of the following holds: (1) either there exists an attack on Pi that causes a mass forced on-chain action and has no uniquely atttributable faults, or (2) there exists an attack on Pi that causes exit size of an honest user to be large.
There exists an inherent “separation” between Plasma Cash and Fungible Plasma. You can’t have best of both worlds here.
Main proof idea
We show that if (1) doesn’t hold and (2) doesn’t hold then you can “compress” a long random string into a short string. Say you have a set of users. You can have a random subset of users from that set. You can compress this description of the random subset into something shorter such that you could decompress it and…. so this is a contradiction of…
Attack
Our attack consits of two epochs, times between commits on the main chain. There’s epoch 1 where we choose a random subset of users. We launch a data unavailability attack. Then in the second epoch, the users will try to exit with their tokens. We prove that if Plasma is secure then the set of users who do not manage to exit has to be equal to the set of targeted users.
We want short exits, and we don’t want to have large non-uniquely attributable data unavailability faults.
In our attack, users will try to exit with their tokens. At the same time users from that subset try to illegally exit with tokens that they don’t have. This is after switching “off” the operator.
Then there’s a set of users that did not manage to exit. Who did not manage to exit? The honest users should be able to exit. If Plasma is secure, then these two sets should be equal.
How do we compress those two sets? We compress(V) in the first epoch. Then we decompress in the second epoch. We apply the second epoch and we look at the set of users who managed to exit.
More in the paper
The reality is more complex. It’s in our paper.
https://eprint.iacr.org/2020/175
Generalization: our result also covers Plasma with some “collateral” on the operator, used to compensate for a dishonest operator.
Conclusion
There are good theoretical reasons why the community is working both on Plasma Cash and Fungible Plasma. Some ideas for how to “get around” this impossibility result is the “defragmentation techniques” for Plasma Cash suggested by Vitalik Buterin…. where you try to merge coins. It works assuming that some users are cooperating with each other. It has some additional assumptions that we don’t have in our paper.
Then there’s another way, “rollups”. Then there’s “semi-trusted committee for ‘data availability’” like StarkDEX. Then they vote outside the blockchain whether the data is really unavailable by the operator.
I think more work on formalization and extensions of Plasma is definitely needed at this stage.
Sponsorship: These transcripts are sponsored by Blockchain Commons.
Disclaimer: These are unpaid transcriptions, performed in real-time and in-person during the actual source presentation. Due to personal time constraints they are usually not reviewed against the source material once published. Errors are possible. If the original author/speaker or anyone else finds errors of substance, please email me at<EMAIL_ADDRESS>for corrections or contribute online via github/git. I sometimes add annotations to the transcription text. These will always be denoted by a standard editor’s note in parenthesis brackets ((like this)), or in a numbered footnote. I welcome feedback and discussion of these as well.
Tweet: Transcript: “Lower Bounds for Off-Chain Protocols: Exploring the Limits of Plasma” https://diyhpl.us/wiki/transcripts/stanford-blockchain-conference/2020/lower-bounds-limits-plasma/ @SteDziembowski @CBRStanford #SBC20


I can't say I've had much experience with leaders who actively try to show compassion to others, but, I certainly feel that those leaders who people liked the most have been the most effective leaders I have had.
I enjoyed it. I find it amazing how well I can visualise something happening, like breathing in my 'aura' and multiplying it back into the world.
Again, I felt as if I could strongly visualise the process, but I didn't feel like I gained very much during this exercise. In fact, the visualisation felt very superficial because of that.
I didn't have the opportunity to work with anyone during Phase 0 - or even make it to any of the check-ins, which is a shame because I feel like the other students are already forming inter-personal bonds with each other.
S - Status: During Phase 0 I have been consistently improving against myself. I did not have a great deal of HTML/CSS experience before this. During the bootcamp, I will continue to do this.
C - Certainty: I have definitely felt the effects of a large amount of uncertainty during (but not related to) Phase 0. I have been extremely stressed because of it and definitely felt as though my decision making skills were hampered because of it.
A - Autonomy: After taking mitigating steps against the uncertainty that was stressing me, I felt much better. I'm glad I had the autonomy to be able to take these steps. I agree with Meng's statement that it's the "helplessness in the face of stress" that actually causes bad feelings.
R - Relatedness: As I wrote earlier, I haven't actually made it to any check-ins for my cohort, and so I haven't met any of them. However, I met and talked to Jack and Harrison from EDA and when I've had to talk to them they have been very nice, friendly, and relatable and that gives me the confidence to ask for anything I need to help me with Phase 0 or EDA in general.
 I have been doing everything alone so I've not had to compromise with anyone else. Harrison at one point 'suggested' a deadline to complete up to Sprint 7 before which was very fair (in fact, I'm completing Sprint 9 now, well before the end of February, which was the deadline).
I talked to my wife about something that had been on my mind recently. She is a very empathetic person and was only supportive of me, and then she also raised some things that had been on her mind too. I think it really helped the both of us to share with each other things that had been stressing us and we know that we both have very suppoortive partners in each other.


Blue lines should all hit the deep red boundary at the same time, then completely cover the light red box when the animation has finished.


Kev and Mar researched on the possibilities of creating an electromagnetic powered tibetan singing bowl synthesysizer
Claudia helped build this project from the ground up. Her work on ceramics inspired the background of this website.
Lia’s caring vegan meals, conversations and artistic linework are present to this day in our home.


The Shatsky lakes are located on the territory of the namesake nature park in the northwest Volyn Polissya and form one of the largest constellations of lakes in Europe, numbering over 30 lakes. This unique natural complex’s main treasure is the lake Svityaz – the second largest natural water body in Ukraine and one of the country’s deepest lakes. Being 58-meter-deep, it is four times deeper than the Azov Sea. Svityaz is often nicknamed as Ukrainian Baikal because of its impressive size.
The lake is saturated by artesian springs and therefore its water is perfectly transparent and well-heated. Combined with clean sandy beaches, it makes this place a perfect family recreation spot. In addition, the climate is very comfortable here: thanks to lighted forests, summer heat is hardly felt on the nature park’s territory.
There is a huge island right in the Svityaz’s center. It is covered with lindens and maples and attracts with its inimitable beauty and mysteriousness. It is popularly known as the Island of Love. The locals often tell an ancient legend, according to which, there is just one way to wade to the island. Whoever finds it and reaches the island will be lucky in love. Another legend states that a marvelous castle used to stand here, but, when strangers attacked, it sank under the water. Later an incredibly beautiful lake spread on castle’s place.
The Shatsky lakes offer multitude of varied recreation opportunities. One can go fishing (dozens of fish species, including bass, pike, bream, catfish and even eel, inhabit the lake waters) or gathering mushrooms and berries, which grow in abundance in Volyn forests. One can also go out boating or sailing a yacht on the lake and admire local natural wonders. In addition, there is an opportunity to play paintball or ride horses on the park’s territory.
A scattering of the emerald Shatsky lakes with crystal pure water that are framed in velvet verdure of primeval woods is rightly considered to be one of the Ukraine’s brightest tourist gems. Picturesque landscapes, rich flora and fauna, and mild curative climate make this territory an ideal place for varied recreation and health improvement.
A scattering of the emerald Shatsky lakes with crystal pure water that are framed in velvet verdure of primeval woods is rightly considered to be one of the Ukraine’s brightest tourist gems. Picturesque landscapes, rich flora and fauna, and mild curative climate make this territory an ideal place for varied recreation and health improvement.
A scattering of the emerald Shatsky lakes with crystal pure water that are framed in velvet verdure of primeval woods is rightly considered to be one of the Ukraine’s brightest tourist gems. Picturesque landscapes, rich flora and fauna, and mild curative climate make this territory an ideal place for varied recreation and health improvement.


There will be only 6 semester not 8 Semester 1 Semester2 Computer science I Computer Science II Discrete Math I Discrete Math II writing course History of Computer Science Art electives Digital Logic Semester 3 Semester 4 Data Structures Testing & Development Machience Language Web Preformance Intro to Databases Algorithms Stat & Prob Free Elect Semester 5 Semester 6 Theory of Automata Computer Arctecture Operating Systems Elect Elect Elect Electives Broswers - A course on how browsers work. Topics will include DOM tree, Render Trees, and differences amoung browers. Will also discuss how browsers are made Search Engines Databases Artifial Intellecgence http://www.cs.manchester.ac.uk/undergraduate/programmes/structure/ http://www.cs.utexas.edu/undergraduate-program/academics/curriculum/degree-plans http://www.msi.unimelb.edu.au/study/undergraduate/computing-software-systems/ http://www.eecs.mit.edu/academics-admissions/undergraduate-programs/course-6-3-computer-science-and-engineering


About Michael
Hello! Thanks for checking out my website. My name is Michael Meldrum and I'm a proud MSU Spartan where I
study Computer Science with an Engineering background. I've gained a particular interest in web development because
I greatly enjoy the unique opportunities afforded by the internet to share information and further the knowledge base
of humanity as a whole. While I continue to be intrigued by the various complexities of data interactions in web
applications, I believe those interactions become far more interesting when tied to the user experience. I am attracted
towards the opportunity to develop data driven websites that provide a simple and accessible interface allowing users
to be productive but also enjoy the experience.
Feel free to contact me at<EMAIL_ADDRESS>Samples
This section contains some sample code I think is worth keeping track of and should be shared.
CSS3 Loading Animation
.loading {
height: 60px;
width: 60px;
margin: 0px auto;
position: relative;
display: inline-block;
vertical-align: middle;
-webkit-animation: rotation 1.5s infinite linear;
-moz-animation: rotation 1.5s infinite linear;
-o-animation: rotation 1.5s infinite linear;
animation: rotation 1.5s infinite linear;
border-left: 6px solid rgba(51,145,124,.15);
border-right: 6px solid rgba(51,145,124,.15);
border-bottom: 6px solid rgba(51,145,124,.15);
border-top: 6px solid rgba(51,145,124,.9);
border-radius: 50%;
}
@-webkit-keyframes rotation {
from {
-webkit-transform: rotate(0deg);
}
to {
-webkit-transform: rotate(359deg);
}
}
@-moz-keyframes rotation {
from {
-moz-transform: rotate(0deg);
}
to {
-moz-transform: rotate(359deg);
}
}
@-o-keyframes rotation {
from {
-o-transform: rotate(0deg);
}
to {
-o-transform: rotate(359deg);
}
}
@keyframes rotation {
from {
transform: rotate(0deg);
}
to {
transform: rotate(359deg);
}
}
This is a pure CSS3 implementation for a loading animation. Just add these definitions to your stylesheet and use the "loading" class on whatever element you want the animation to appear. I have also created a helper JavaScript library that makes this implementation quickly reusable throughout a structured website.


First class
-
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{{seat.column}}{{seat.row}}
${{seat.price}}{{seat.column}}{{seat.row}}
+
-
${{seat.price}}
{{seat.column}}{{seat.row}}
${{seat.price}}{{seat.column}}{{seat.row}}
+
Business
-
${{seat.price}}
{{seat.column}}{{seat.row}}
${{seat.price}}{{seat.column}}{{seat.row}}
+
-
${{seat.price}}
{{seat.column}}{{seat.row}}
${{seat.price}}{{seat.column}}{{seat.row}}
+
Economy
-
${{seat.price}}
{{seat.column}}{{seat.row}}
${{seat.price}}{{seat.column}}{{seat.row}}
+
-
${{seat.price}}
{{seat.column}}{{seat.row}}
${{seat.price}}{{seat.column}}{{seat.row}}
+
Basic Economy
-
${{seat.price}}
{{seat.column}}{{seat.row}}
${{seat.price}}{{seat.column}}{{seat.row}}
+
-
${{seat.price}}
{{seat.column}}{{seat.row}}
${{seat.price}}{{seat.column}}{{seat.row}}
+


Season {{episodeDetail.season}}
Episode Details
Season {{episodeDetail.season}}
Episode {{episodeDetail.episode}}
Title "{{episodeDetail.title}}"
Mood
{{episodeDetail.mood | titlecase}}
Screenplay / Writing
{{episodeDetail.writer}}
Director
{{episodeDetail.director}}
Summary
{{episodeDetail.episodeSummary}}
Tropes
Main Characters
Hercule Poirot
Captain Arthur Hastings
Ms. Felicty Lemon
Inspector James Japp
Ms. Ariadne Oliver
George the Valet
Supporting Characters
{{char}}
Crimes
{{c.criminalAct}}
Perpetrator
{{c.perpetrator}}
Victim
{{c.victim}}
Means: {{c.means}}
Motive: {{c.motive}}
Opportunity: {{c.opportunity}}


Modular foreign function bindings
One of the most frequent questions about MirageOS from developers is “do I really need to write all my code in OCaml”? There are, of course, very good reasons to build the core system in pure OCaml: the module system permits reusing algorithmic abstractions at scale, and OCaml’s static type checking makes it possible to enforce lightweight invariants across interfaces. However, it’s ultimately necessary to support interfacing to existing code, and this blog post will describe what we’re doing to make this possible this without sacrificing the security benefits afforded by unikernels.
A MirageOS application works by abstracting the logic of the
application from the details of platform that it is compiled for.
The mirage
CLI tool parses a configuration file that represents the
desired hardware target, which can be a Unix binary or a specialized
Xen guest OS. Our foreign function interface design elaborates on
these design principles by separating the description of the C
foreign functions from how we link to that code. For instance, a
Unix unikernel could use the normal ld.so
to connect to a shared
library, while in Xen we would need to interface to that C library
through some other mechanism (for instance, a separate VM could be
spawned to run the untrusted OpenSSL code). If you’re curious about
how this works, this blog post is for you!
Introducing ctypes
ocaml-ctypes (“ctypes” for short) is a library for gluing together OCaml code and C code without writing any C. This post introduces the ctypes library with a couple of simple examples, and outlines how OCaml’s module system makes it possible to write high-level bindings to C that are independent of any particular linking mechanism.
Hello, C
Binding a C function using ctypes involves two steps.
- First, construct an OCaml value that represents the type of the function
- Second, use the type representation and the function name to resolve and bind the function
For example, here’s a binding to C’s puts
function, which prints a string to
standard output and returns the number of characters written:
let puts = foreign "puts" (string @-> returning int)
After the call to foreign
the bound function is available to OCaml
immediately. Here’s a call to puts
from the interactive top level:
# puts "Hello, world";;
Hello, world
- : int = 13
<Hello-C/>
Now that we’ve had a taste of ctypes, let’s look at a more realistic example: a program that defines bindings to the expat XML parsing library, then uses them to display the structure of an XML document.
We’ll start by describing the types used by expat. Since ctypes represents C types as OCaml values, each of the types we need becomes a value binding in our OCaml program. The parser object involves an incomplete (abstract) struct definition and a typedef for a pointer to a struct:
struct xml_ParserStruct;
typedef xml_ParserStruct *xml_Parser;
In ctypes these become calls to the structure
and ptr
functions:
let parser_struct : [`XML_ParserStruct] structure typ = structure "xml_ParserStruct"
let xml_Parser = ptr parser_struct
Next, we’ll use the type representations to bind some functions. The
XML_ParserCreate
and
XML_ParserFree
functions construct and destroy parser objects. As with puts
, each
function binding involves a simple call to foreign
:
let parser_create = foreign "XML_ParserCreate"
(ptr void @-> returning xml_Parser)
let parser_free = foreign "XML_ParserFree"
(xml_Parser @-> returning void)
Expat operates primarily through callbacks: when start and end elements are encountered the parser invokes user-registered functions, passing the tag names and attributes (along with a piece of user data):
typedef void (*start_handler)(void *, char *, char **);
typedef void (*end_handler)(void *, char *);
In ctypes function pointer types are built using the funptr
function:
let start_handler =
funptr (ptr void @-> string @-> ptr string @-> returning void)
let end_handler =
funptr (ptr void @-> string @-> returning void)
We can use the start_handler
and end_handler
type representations to bind
XML_SetElementHandler
, the callback-registration function:
let set_element_handler = foreign "XML_SetElementHandler"
(xml_Parser @-> start_handler @-> end_handler @-> returning void)
The type that OCaml infers for set_element_handler
reveals that the function
accepts regular OCaml functions as arguments, since the argument types are
normal OCaml function types:
val set_element_handler :
[ `XML_ParserStruct ] structure ptr ->
(unit ptr -> string -> string ptr -> unit) ->
(unit ptr -> string -> unit) -> unit
There’s one remaining function to bind, then we’re ready to use the
library. The
XML_Parse
function performs the actual parsing, invoking the callbacks when tags
are encountered:
let parse = foreign "XML_Parse"
(xml_Parser @-> string @-> int @-> int @-> returning int)
As before, all the functions that we’ve bound are available for use
immediately. We’ll start by using them to define a more idiomatic OCaml entry
point to the library. The parse_string
function accepts the start and end
callbacks as labelled arguments, along with a string to parse:
let parse_string ~start_handler ~end_handler s =
let p = parser_create null in
let () = set_element_handler p start_handler end_handler in
let _ = parse p s (String.length s) 1 in
parser_free p
Using parse_string
we can write a program that prints out the names of each
element in an XML document, indented according to nesting depth:
let depth = ref 0
let start_handler _ name _ =
Printf.printf "%*s%s\n" (!depth * 3) "" name;
incr depth
let end_handler _ _ =
decr depth
let () =
parse_string ~start_handler ~end_handler (In_channel.input_all stdin)
The full source of the program is available on github.
Here’s the program in action:
$ ocamlfind opt -thread -package core,ctypes.foreign expat_example.ml \
-linkpkg -cclib -lexpat -o expat_example
$ wget -q http://openmirage.org/blog/atom.xml -O /dev/stdout \
| ./expat_example
feed
id
title
subtitle
rights
updated
link
link
contributor
email
uri
name
[...]
Since this is just a high-level overview we’ve passed over a number of details. The interested reader can find a more comprehensive introduction to using ctypes in Chapter 19: Foreign Function Interface of Real World OCaml.
Dynamic vs static
Up to this point we’ve been using a single function, foreign
, to
make C functions available to OCaml. Although foreign
is simple to
use, there’s quite a lot going on behind the scenes. The two
arguments to foreign
are used to dynamically construct an OCaml
function value that wraps the C function: the name is used to resolve
the code for the C function, and the type representation is used to
construct a call frame appropriate to the C types invovled and to the
underlying platform.
The dynamic nature of foreign
that makes it convenient for
interactive use, also makes it unsuitable for some environments.
There are three main drawbacks:
-
Binding functions dynamically involves a certain loss of safety: since C libraries typically don’t maintain information about the types of the functions they contain, there’s no way to check whether the type representation passed to
foreign
matches the actual type of the C function. -
Dynamically constructing calls introduces a certain interpretative overhead. In mitigation, this overhead is much less than might be supposed, since much of the work can be done when the function is bound rather than when the call is made, and
foreign
has been used to bind C functions in performance-sensitive applications without problems. -
The implementation of
foreign
uses a low-level library, libffi, to deal with calling conventions across platforms. While libffi is mature and widely supported, it’s not appropriate for use in every environment. For example, introducing such a (relatively) large and complex library into Mirage would compromise many of the benefits of writing the rest of the system in OCaml.
Happily, there’s a solution at hand. As the introduction hints, foreign
is
one of a number of binding strategies, and OCaml’s module system makes it easy
to defer the choice of which strategy to use when writing the actual code.
Placing the expat
bindings in a functor (parameterised module) makes it
possible to abstract over the linking strategy:
module Bindings(F : FOREIGN) =
struct
let parser_create = F.foreign "XML_ParserCreate"
(ptr void @-> returning xml_Parser)
let parser_free = F.foreign "XML_ParserFree"
(xml_Parser @-> returning void)
let set_element_handler = F.foreign "XML_SetElementHandler"
(xml_Parser @-> start_handler @-> end_handler @-> returning void)
let parse = F.foreign "XML_Parse"
(xml_Parser @-> string @-> int @-> int @-> returning int)
end
The Bindings
module accepts a single parameter of type FOREIGN
, which
encodes the binding strategy to use. Instantiating Bindings
with a module
containing the foreign
function used above recovers the
dynamically-constructed bindings that we’ve been using so far. However, there
are now other possibilities available. In particular, we can instantiate
Bindings
with code generators that output code to expose the bound functions
to OCaml. The actual instantiation is hidden behind a couple of convenient
functions, write_c
and write_ml
, which accept Bindings
as a parameter
and write to a formatter:
Cstubs.write_c formatter ~prefix:"expat" ~bindings:(module Bindings)
Cstubs.write_ml formatter ~prefix:"expat" ~bindings:(module Bindings)
Generating code in this way eliminates the concerns associated with constructing calls dynamically:
-
The C compiler checks the types of the generated calls against the C headers (the API), so the safety concerns associated with linking directly against the C library binaries (the ABI) don’t apply.
-
There’s no interpretative overhead, since the generated code is (statically) compiled.
-
The dependency on libffi disappears altogether.
How easy is it in practice to switch between dynamic and static binding strategies? It turns out that it’s quite straightforward, even for code that was originally written without parameterisation. Bindings written using early releases of ctypes used the dynamic strategy exclusively, since dynamic binding was then the only option available. The commit logs for projects that switched over to static generation and linking (e.g. ocaml-lz4 and async-ssl) when it became available show that moving to the new approach involved only straightforward and localised changes.
Local vs remote
Generating code is safer than constructing calls dynamically, since it
allows the C compiler to check the types of function calls against
declarations. However, there are some safety problems that even C’s
type checking doesn’t detect. For instance, the following call is
type correct (given suitable definitions of p
and q
), but is
likely to misbehave at run time:
memcpy(p, q, SIZE_MAX)
In contrast, code written purely in OCaml detects and prevents attempts to write beyond the bounds of allocated objects:
# StringLabels.blit ~src ~dst ~src_pos:0 ~dst_pos:0 ~len:max_int;;
Exception: Invalid_argument "String.blit".
It seems a shame to weaken OCaml’s safety guarantees by linking in C code that can potentially write to any region of memory, but what is the alternative?
One possibility is to use privilege separation to separate
trusted OCaml code from untrusted C functions. The modular design of
ctypes means that privilege separation can be treated as one more
linking strategy: we can run C code in an entirely separate process
(or for Mirage/Xen, in a separate virtual machine), and instantiate
Bindings
with a strategy that forwards calls to the process using
standard inter-process communication. The remote calling strategy is
not supported in the current release of ctypes, but
it’s scheduled for a future version. As with the switch from dynamic
to static bindings, we anticipate that updating existing bindings to
use cross-process calls will be straightforward.
This introductory post should give you a sense of the power of the unikernel approach in Mirage. By turning the FFI into just another library (for the C interface description) and protocol (for the linkage model), we can use code generation to map application logic onto the privilege model most suitable for the target hardware platform. This starts with Unix processes, continues onto Xen paravirtualization, and could even extend into CHERI fine-grained compartmentalization.
Further examples
Although ctypes is a fairly new library, it’s already in use in a number of projects across a variety of domains: graphics, multimedia, compression, cryptography, security, geospatial data, communication, and many others. Further resources (documentation, forums, etc.) are available via the home page.
- Irmin 0.12 with portable filesystem watching released
- MirageOS Summer 2016 Hackathon roundup
- MirageOS Summer 2016 Hackathon announcement, and talk roundup
- MirageOS Spring 2016 Hackathon!
- MirageOS security advisory 00: mirage-net-xen
- Introducing Functoria
- Run Mirage Unikernels on KVM/QEMU with Solo5
- MirageOS hackathon
- Introducing Charrua — a DHCP implementation
- Unikernel.org


{% load static %}
Welcome to my first attempt at wrting storing and reading objects! This is a moc library, storing the title, author, number pages, and whether or not you have read the book. The total library stored on your computer will be shown in the bottom section, while the current search function is shown in the above screen outlined by the thin white border. All library changes will be stored on your local library. So when you come back they will still be there! If you want to delete all in your cache you can click the button that is labeled Clear Data on Local Machine


${require('./templates/header.html')}
${require('./templates/nav-menu.html')}People make a company and the right people make the company a success. Our team of dedicated professionals' sole purpose is to provide professional service, yet on a very personal level. Each customer's needs are unique and we take the time to listen, to ensure the solutions offered are in the customer's best interest. Long term relationships are our goal.
At Big Sky Internet Design “You are more than just a customer”.
Tom and Carrie, owners of Exceleration Designs, Inc, have been designing websites since 1998. Big Sky Internet Design and Aggieland Website Design are divisions of Exceleration Designs. Big Sky Internet Design is the backbone of the business and has been highly successful by offering unsurpassed levels of customer service. Ask ANY of our customers!
Tom Bruch
Carrie Bruch
Debbie Damiano
Linda Pritchett
Jessica Bruch
JT Bruch
Kelsey Hellman
Kristen Ducey


Install firewalls between any wireless networks and the cardholder data environment. Configure these firewalls to only allow traffic necessary for business purposes.
Wireless access points may be compromised and an attacker may be using them. To prevent sensitive data from leaking out through a compromised wireless network, a firewall should be used to filter traffic between the cardholder data environment and the wireless network.
Install and configure a firewall between each wireless network and the cardholder data environment. Refer to the vendor’s documentation or technical support for installation and configuration instructions.


{% extends 'base.html' %} {% block content %}
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Username {{ form.username }}
Password {{ form.password }}


Eye of the Beholder (2000) Ewan McGregor, Ashley Judd, k.d. lang, Jason Priestley, Genvieve Bujold, Patrick Bergen. Screenplay by Stephan Elliot, based on the novel by Marc Behm. Directed by Stephan Elliot. 110 minutes. Rated R, 1.5 stars (out of five stars)
Review by Ed Johnson-Ott, NUVO Newsweekly www.nuvo.com Archive reviews at http://us.imdb.com/ReviewsBy?Edward+Johnson-Ott To receive reviews by e-mail at no charge, send subscription requests to<EMAIL_ADDRESS>or e-mail<EMAIL_ADDRESS>with the word "subscribe" in the subject line.
After scanning a rave review of "Eye of the Beholder," I went to a press screening of the psychological thriller with high hopes.  Following an intriguing start, "Eye of the Beholder" soon deteriorates into an incomprehensible mess, and a pretentious one to boot.  There's a somber child in this movie as well, one who was probably thinking, "I see a dead script."
The film, which stars Ashley Judd as a serial killer and Ewan McGregor as an obsessed surveillance expert, was shot well before the two actors achieved mainstream success in, respectively, "Double Jeopardy" and "Star Wars: The Phantom Menace." Released now to exploit their fame, word of mouth will likely insure a quick fade for the noir flick, despite the inclusion of a nude scene from the extremely attractive Judd. At least the producers were thoughtful enough to place that segment at the beginning of the film, so when it hits cable, those who want to see Ashley naked can do so without having to suffer through much of the story.
Based on the acclaimed 1980 novel by Marc Behm, "Eye of the Beholder" follows a British Secret Service agent called The Eye (McGregor) as he investigates the possible blackmail of his employer's son. While spying on the young man, he watches in horror as Joanna Eris (Judd) hacks up the guy with a butcher knife. Instead of calling the cops, he follows her from city to city like a lovestruck puppy as she turns more unsuspecting men into sushi.
Why? Well, apparently it's some sort of Jerry Springer deal where one incredibly fucked-up person finds another incredibly fucked-up person irresistible. You see, after each slaughter, Joanna screams about her daddy, who deserted her when she was a child. The Eye can relate; years ago, his wife took their young daughter and left, frustrated over his obsession with work. In fact, The Eye often sees visions of his daughter, occasionally two at once. Interestingly enough, while he does chat with the hallucinations from time to time, he remains preoccupied with business. So much for learning from your mistakes.
He is able, however, to devote his full attention to Joanna. After all, what inexpressive guy who lost his family wouldn't get the hots for a man-slashing nut case? It's a love connection!
Things were different in the book. The Eye was a middle-aged man who followed Joanna because he believed she might actually be his long lost daughter. But writer/director Stephan Elliot ("The Adventures of Priscilla: Queen of the Desert") didn't want to waste his time with something as pedestrian as a faithful adaptation of the source material. Instead, he takes out his Crayola and creates the kind of weird-ass trifle David Lynch might have done in grammar school. For scene transitions, he zooms in on snow globes depicting the next locale. The effect is engaging at first, but he repeats it for the entire film. After the sixth or seventh snow globe, I was ready to take an ax to the nearest souvenir stand.
Elliot desperately wants to be Alfred Hitchcock, but he can't even pull off a decent Brian De Palma. From the ham-handed visual underscoring of his "guardian angel" theme to a "Look! I saw 'Vertigo!'" scene in a bell tower, Elliot directs with the finesse of Homer Simpson at an all-you-can-eat pork chop dinner.
Somehow, Ashley Judd comes through it all relatively unscathed. Despite being forced to sport a variety of bad wigs and shriek her motivations with each new murder, she still imbues Joanna with a degree of depth beyond anything in Elliot's murky screenplay. And, although the insular nature of his character gives him little room to move, Ewan McGregor deserves credit just for keeping a straight face through this nonsense, especially when his character must play super sleuth while wearing an attention-getting bright red jacket.
After the "Eye of the Beholder" screening, I expressed relief to my colleague that I would have a few days to process what I'd seen. After considerable reflection, I've come to the conclusion that there is little to process. "Eye of the Beholder" wants to be an art film and a thriller. It fails at both aspirations. If you'll pardon the expression, there is far less here than meets the eye.
© 2000 Ed Johnson-Ott
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The time has come for me to update the enormously useful Hooting Yard Pontiff Mnemonic. Before I wrestle with the most appropriate F word, however, I think I am right in saying that there could be no more Hooting Yardy Pontiff than a one-lunged Jesuit bus passenger.
UPDATE : I managed to pluck from the dictionary the definitive F word to add to the Pontiff Mnemonic just in time for today's episode of Hooting Yard On The Air on ResonanceFM. You can find out what the word is by listening to the show, archived on soundcloud here.


Air quality improves in Delhi, light rains predicted
by PTIThe air quality in the national capital was recorded in the "satisfactory" category on Friday morning.
The Air Quality Index stood at 79.
The MeT department has predicted light rains in later parts of the day.
An AQI between 0-50 is considered 'good', 51-100 'satisfactory', 101-200 'moderate', 201-300 'poor', 301-400 'very poor' and 401-500 'severe'. An AQI above 500 falls in the 'severe plus' category.


| copy_to.src_sql {dbplyr} | R Documentation |
This is an implementation of the dplyr copy_to()
generic and it mostly
a wrapper around DBI::dbWriteTable()
.
It is useful for copying small amounts of data to a database for examples, experiments, and joins. By default, it creates temporary tables which are only visible within the current connection to the database.
## S3 method for class 'src_sql' copy_to( dest, df, name = deparse(substitute(df)), overwrite = FALSE, types = NULL, temporary = TRUE, unique_indexes = NULL, indexes = NULL, analyze = TRUE, ..., in_transaction = TRUE )
dest |
remote data source |
df |
A local data frame, a |
name |
name for new remote table. |
overwrite |
If |
types |
a character vector giving variable types to use for the columns. See https://www.sqlite.org/datatype3.html for available types. |
temporary |
if |
unique_indexes |
a list of character vectors. Each element of the list will create a new unique index over the specified column(s). Duplicate rows will result in failure. |
indexes |
a list of character vectors. Each element of the list will create a new index. |
analyze |
if |
... |
other parameters passed to methods. |
in_transaction |
Should the table creation be wrapped in a transaction? This typically makes things faster, but you may want to suppress if the database doesn't support transactions, or you're wrapping in a transaction higher up (and your database doesn't support nested transactions.) |
Another tbl_lazy
. Use show_query()
to see the generated
query, and use collect()
to execute the query
and return data to R.
library(dplyr, warn.conflicts = FALSE) df <- data.frame(x = 1:5, y = letters[5:1]) db <- copy_to(src_memdb(), df) db df2 <- data.frame(y = c("a", "d"), fruit = c("apple", "date")) # copy_to() is called automatically if you set copy = TRUE # in the join functions db %>% left_join(df2, copy = TRUE)


This Event
Welcome Talk
Find the slides from the welcome talk at
https://hacksoc.net/hacktoberfest-slides


{% extends 'layout.html' %} {% block body %}
This webpage will take the input of a fake news and represent the spread in social medias


#
# This is not all-encompasing, but may help automate what is worth
# looking at and what can be immediately skipped over
#
echo "#------------------------------------------------#"
echo "# SUID Files Enumeration Script #"
echo "#------------------------------------------------#"
echo " "
#Find SUID files and store them in SUID_FILES.txt
echo "[+] Dumping SUID files list into SUID_FILES.txt.."
find / \( -perm -4000 \) -exec ls -ld {} \; 2>/dev/null | awk '{print $9}' > SUID_FILES.txt
sleep 2
#loop through common linux binaries and then remove them from SUID_FILES.txt
echo "[+] Trimming common SUID files from SUID_FILES.txt..."
for bname in '/umount/d' '/su/d' '/mount/d' '/sudo/d' '/passwd/d' '/exim4/d' '/chfn/d' '/chsh/d' '/procmail/d' '/newgrp/d' '/ping/d' '/ntfs-3g/d' '/pppd/d' '/pkexec/d' '/ssh-keysign/d' '/dbus-daemon-launch-helper/d' '/uuidd/d' '/pt_chown/d' '/at/d' '/mtr/d' '/dmcrypt-get-device/d' '/X/d' '/traceroute6.iputils/d' '/polkit-resolve-exe-helper/d' '/polkit-set-default-helper/d' '/polkit-grant-helper-pam/d'
do
sed -i $bname ./SUID_FILES.txt
done
sleep 2
echo "[+] Preform strings on the following binaries.."
echo " "
echo "#------------------------------------------------#"
for line in $(cat SUID_FILES.txt); do
echo " * "$line
done
echo "#------------------------------------------------#"
echo " "
sleep 5
# Perform string command on uncommon SUID binaries
for line in $(cat SUID_FILES.txt); do
echo " "
echo "#------------------------------------------------#"
echo $line
echo "#------------------------------------------------#"
strings $line
echo " "
sleep 5
done
echo " "
echo "#------------------------------------------------#"
echo "# Done. Happy hunting! #"
echo "#------------------------------------------------#"


Schools in New Delhi shut until Nov 5 as air pollution severe
NEW DELHI: Schools in the Indian capital will be shut until Nov 5, the city government said on Friday (Nov 1), as residents breathed the season's worst air for a third straight day.
As farm fires from New Delhi's neighboring states sent swathes of smoke into the capital, the city's chief minister Arvind Kejriwal ordered schools to be closed, the minister said in a tweet he posted in Hindi.
Earlier on Friday, a government-appointed environment panel declared Delhi's air pollution a public health emergency, according to report by Reuters partner ANI that quoted a letter from the Environment Pollution Control Authority.
"This is a public health emergency as air pollution is now hazardous and will have adverse health impacts on all particularly the children," ANI quoted the letter.
READ: As Delhi breathes season's worst air, cricketers hit the nets under smoggy skies
Government-monitored indices that track air pollution hit 500 in several parts of the capital, the maximum recorded by the government's Central Pollution Control Board.
The index measures the levels of PM 2.5, tiny particulate matter that goes deep into the lungs.
Levels above 400 indicate severe conditions that put people with healthy lungs as well as those with respiratory illnesses at risk.
The government will also restrict the number of private vehicles in the city from next week under an "odd-even" scheme based on the number plates.


{% extends 'basics/base.html' %} {% block content %}
An Email should have been send to your Emailaddress.


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| Module | statements | missing | excluded | branches | partial | coverage |
|---|---|---|---|---|---|---|
| Total | 430 | 118 | 18 | 74 | 2 | 70% |
| IO.py | 17 | 4 | 0 | 2 | 0 | 68% |
| __main__.py | 7 | 7 | 0 | 4 | 0 | 0% |
| abstract_py2UML_builder.py | 22 | 5 | 0 | 0 | 0 | 77% |
| commandLine.py | 87 | 87 | 0 | 26 | 0 | 0% |
| component.py | 5 | 1 | 0 | 0 | 0 | 80% |
| decorations\cleanup.py | 25 | 0 | 0 | 8 | 1 | 97% |
| decorations\get_files.py | 29 | 0 | 0 | 12 | 0 | 100% |
| decorations\make_graph.py | 18 | 0 | 0 | 2 | 0 | 100% |
| decorations\show_after.py | 17 | 0 | 0 | 4 | 0 | 100% |
| decorator.py | 8 | 1 | 0 | 0 | 0 | 88% |
| diagramMaker.py | 26 | 0 | 2 | 2 | 0 | 100% |
| director.py | 16 | 0 | 0 | 6 | 0 | 100% |
| exceptions.py | 23 | 9 | 0 | 0 | 0 | 61% |
| pieChart.py | 12 | 0 | 0 | 0 | 0 | 100% |
| py2UML.py | 23 | 0 | 16 | 2 | 0 | 100% |
| py2UML_builder.py | 19 | 0 | 0 | 0 | 0 | 100% |
| py_reverse.py | 2 | 2 | 0 | 0 | 0 | 0% |
| setup.py | 2 | 2 | 0 | 0 | 0 | 0% |
| tests\modelTests.py | 72 | 0 | 0 | 6 | 1 | 99% |
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